Actron CP9190 manual From the Special Tests Menu Select Field Service

GM Historic (OBD I) Diagnostics

Field Service

✓Field Service is a special diagnostic mode to monitor fuel system operation and read DTCs. Some GM service manuals may refer to this mode as the Field Service Mode Check. This mode works on vehicles equipped with a 12-pin ALDL connector with a wire present in pin-B, Diagnostic or Test Enable. The Scan Tool enters this mode by grounding pin-B: shorting pin-B to pin -A (ground).

✓Field Service mode can be operated with KOEO or KOER.

✓Vehicles equipped with climate control computers do not use Field Service mode.

✓Some 1994 and 1995 vehicles equipped with a 12-pin ALDL connector with pins A and B shorted will not cause the CHECK ENGINE light to flash codes.

From the Special Tests Menu:

1.Select Field Service.

•Use UP or DOWN arrow key until Field Service is highlighted.

•Press ENTER.

2.Check vehicle malfunction indicator lamp (MIL).

•Turn ignition key on, but do not start engine. The CHECK ENGINE light should flash. •Select YES to continue.

•If the light does not illuminate, either the vehicle does not support this test mode, the lamp is burned-out or circuit problems exist.

Special Tests Menu

￿Field Service Review Data Print Data Tool Setup

Test Availability

Does your CHECK

ENGINE light flash?

<Yes> No

5

✓It is difficult to know exactly which GM vehicles use the Field Service mode. It is possible to have the Field Service mode function on the Special Tests Menu, and it not be applicable.

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